1. Field of the Invention
This invention relates to cassette holder moving mechanisms for vertically moving a cassette holder holding a cassette case that is held substantially in a horizontal position in a magnetic recording and reproduction apparatus in which the cassette holder is movably supported on a slide chassis.
2. Description of the Background Art
Among magnetic recording and reproduction apparatus, a so-called 8-mm video apparatus uses a magnetic tape. In such an 8-mm video apparatus, the slide chassis can hold a cassette case in which a wound magnetic tape is disposed. The slide chassis can be moved by a built-in vertical moving mechanism to an eject position where the cassette holder is ejected out from the video main unit, and to a play position by a slide mechanism. At the play position, the magnetic tape can be pulled out from the cassette case to run for recording or reproduction.
The cassette holder is vertically moved relative to the slide chassis by moving mechanisms provided on two opposing sides so that the surfaces of the cassette case are moved in parallel.
The cassette holder provides vertical and substantially parallel movement due to the moving mechanism provided on the opposing sides. Therefore, if the force on one of the moving mechanisms is biased, the cassette holder does not provide movement in parallel, and the setting of the cassette tends to be unstable. Furthermore, since a lock mechanism for fixing the descending end position of the cassette holder is provided at only one side of the moving mechanisms, the other side of the cassette holder tends to be moved up by a counter-force. Furthermore, when both moving mechanisms are synchronized by a rack and pinion mechanism, movement of the pinion is small relative to vertical movement of the arm in a condition where the arm is nearly horizontal, that is, close to a cassette holder locking condition. As a result, there is a problem in that a backlash between the rack and pinion tends to produce a dead zone to the vertical movement.